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Home , Danthonia, Danthonia californica, Pappophorum, Pentameris, Schismus

cleistogamy occurs have both istic and well-known festucoid Cleisfogenes in ’ chasmogamous flowers and tribes as the Festuceae, Aveneae, either one or two types of cleis- Phalarideae, Agrostideae, and A. K. DOBRENZ AND A. A. BEETLE togamous flowers. When the Hordeae. This emphasizes the Assistant Professor of agronomy and cleistogamous florets are born mesophytic northern origin of Professor of Range Management, re- on the terminal panicle but show the festucoid group in contrast spectively, University of , strong differences (usually in to the arid southern dispersals so Laramie. another size or loss of lodicules) , characteristic of the species and the are called dimorphic. tribes in which cleistogenes are Highlight According to Arber (1934), present, e.g., Stipeae (Stipa Zeu- Cleisiogamy is the behavior of flowers which do nof open but which “Cleistogamic cotricha), Sporoboleae (Sporobo- produce fruits and seeds as a result sometimes take the minimal form Zus vaginiflorus,) Eragrosteae of self-fertilization. Danthonia cali- (Leptochloa dubia), Danthoneae jornica, D. unispicata, and D. spicata of ‘cleistogenes’-solitary, sessile, were found to be cleisfogamous, but single flowers, with lemma and (), and D. intermedia produced no cleisfo- palea, but without the usual Pappophoreae (Cottea pappo- genes in Jackson Hole, Wyoming. Cleisfogenes were capable of produc- outer empty glumes.” Thesecleis- phoroides). ing new plants and therefore may be togenes occur in the lower leaf- The phylogenetic relationships a means for reproduction for cleisfo- sheaths of the flowering culms among the above tribes are suffi- gamous species in Jackson Hole. or in the axils of the lower ciently diverse to leave open the Cleistogamy is understood to branches. Two or three-flowered question as to whether the pres- be the behavior of flowers which spikelets may be involved. The ence of cleistogenes is an ex- do not open but which produce cleistogamous florets character- ample of epharmonic develop- fruits and seeds as a result of istic of Amphicarpon and Chloris ment. Cleistogenes are not char- self-fertilization. Cleistogamy chloridea are of the same order acteristic only of North Ameri- . (literally closed marriage) re- as cleistogenes, but since they can arid areas. They occur also in sults in a type of fertilization are born on underground culms all other arid areas of the globe. called autogamy. More simply, they would seem to need a sepa- They may occur in these places cleistogamy refers to florets that rate term. Since none has pre- in the same species when it is never open, making cross-pol- viously been used it is suggested able to bridge the gap (e.g., lination impossible. In many that they be called rhizan- Parodi reported that in South chasmogamous (open-polli- thogenes (or rhizanthogames) . America dlesvauxii nated) flowers self-pollination In all cases where at least two bears cleistogenes) , or sometimes occurs, but the possibility of types of cleistogamous florets is related species (e.g., Chase re- cross-pollination always pres- occur on the same , the ported that in the Old World ent. plants are referred to as amphi- boreale and P. Investigations and descriptions gamic. brachystachyum bear cleisto- of cleistogamy date back to the In some cases it would appear genes). year 1539 (according to Uphof, that cleistogenes disperse with Cleistogene formation is, with- 1938)) when Hieronymus Bock difficulty, especially when the in bounds, an epharmonic de- mentioned in his publication, basal sheaths are persistent and velopment in grasses. The cases “Neue Kreuter Buch,” on barley, the flowering culms are not de- of facultative cleistogamy are that some grasses were able to hiscent. However, there is a ten- probably very numerous and sel- produce fruits without showing dency for an association between dom reported. They represent an the various parts of the flowers. the presence of cleistogamous evolutionary tendency through- Linnaeus (1753) also was con- spikelets and dehiscent inflores- out the grass family. Dimorphic scious of this closed flower con- cences (e.g., Danthonia, Sporo- cleistogamy is more often re- dition as determined from his bolus, Scleropogon), which some- ported but also shows closer as- description of Panicurn clande- times aids in cleistogenic dis- sociation with plants occurring stinum, published in “Species persal. Perhaps more important in warm, arid areas. Cleistogene Plantarum.” than dispersal is their formation formation is the most restricted In the study of cleistogamy in under severe overgrazing, allow- (1) in number of tribes in which grasses one of the most difficult ing for reproduction (cf. Dyk- it occurs, (2) in number of spe- problems is that of definitions. sterhuis, 1945). cies in which it occurs, and (3) The majority of grasses in which Phylogenetically, the distribu- in geographic area. 1Published with approval o j the Di- tion of cleistogenes is interesting. Danfhoneae rector, Wyoming Agricultural Ex- Perhaps there ‘is significance in Primitive distributions in the periment Station, as Journal Article the apparent absence of this Gramineae are primarily tropical or No. 283. character from such character- subtropical, e.g., those of the tribes

292 CLEISTOGENES 293

Bambuseae, Olyroideae, and Oryzeae. and D. obtorta), the Rocky Moun- Albany County, and transplanted on The groups second most primitive, tains (D. parryi, D. unispicata), and the Biological Research Station at at least in evolutionary origin and eastern North America (D. com- Moran for comparative studies. distribution pattern, are those which pressa and D. sericea). Eastern North Cleistogene Location, Attachment, are most abundant in the southern America and the Rocky Mountains and Number.-Early in the growing hemisphere and are lacking at high are related to each other by two season, cleistogenes ,are not readily altitudes in the northern hemis- similarly disjunct distributions in evident. Dissection shows that these phere; e.g., Danthoneae is one of the D. spicata and D. intermedia. small seeds originate at the joints of more recently accepted tribes of the In South America another four the flowering culms and are wrapped Gramineae, the recognition of which centers of distribution occur, the by the base of the sheaths. Later in has done much for the understand- Andes (four or five species are well- the growing season, cleistogenes ap- ing of naturally drawn borders known species, but 17 scientific pear as small bumps which can be around the remaining tribes. names are based on types from seen plainly at joints where they Danthoneae are now more abun- here), the delta region of the Parana occur (Fig. 1). dant in temperate regions. More spe- (two species), subtropical D. spicata is characteristically a cies survive in the southern hemis- (about five names but little known monocleistogamous species with sel- phere than in the northern. The his- about the species), and finally the dom more than one cleistogene at a tory of Danthoneae distribution must paramos of Venezuela, and joint. Each small seed, enclosed in a be presumed to be early, to have Brazil (D. secundiflora). lemma and a palea, seems to be involved the same southern routes The North and South Americlan sessile. The prophyllum is present which were taken by the tropical species are as strongly related to in the form of two indurate, wing- groups, but, on the other hand, to be each other as they are to any of the like structures which occur at the independent of the parallelism found Old World types. This leads to the point of attachment. in the Bambuseae, Olyroideae and conclusion that they arrived in the D. californica and D. unispicata Oryzeae. Anisopogon supplies the New World at one time. That the are termed polycleistogamous, since geographical link between South North American species were de- more than one cleistogene occurs and Australia. Two genera rived from the South American and at each joint on the flowering culm. are found in India (Danthonidium dispersed across the tropics is sug- Both of these species produce cleis- and Hubbardia), Notochloe in Aus- gested by (1) absence of Arctic and togenes which are enclosed in a lem- tralia, and Monostachya ‘occurs in subarctic species, (2) absence of the ma and a palea. The cleistogenes are the Philippines and New Guinea. from northern and borne on a rachilla which arises at However, the bulk of the genera and Asia, (3) presence of its distribution the base of the lowermost cleistogene species of the Danthoneae are Afri- to the tip of South America, (4) its and serves as a means of attachment can, e.g., (annuals now in- presence in the tropics of Brazil, the for the others. The basal cleistogene troduced in the New World), Plagio- islands around the Claribbean Sea, in these two species has the char- chloa, Asthenatherum, , and in central Mexico, (5) strong acteristic indurate, wing-like struc- , Afrachneria, Chaetobro- representation of a diploid chromo- tures; but cleistogenes produced on mus, Urochlaena, Lasiochloa, Priona- some number of 36 in both regions, the terminal portion of the rachilla thium, Alloechaete, Phaenanthoeci- (6) presence of cleistogamous types lack these appendages. urn, and Poagrostis. The New Zea- in both regions, (7) presence of the The cleistogamous condition is and land flora includes , types with bicellular hairs easiest to recognize in D. californica. Notodanthonia, Erythranthera and dumbbell-shaped siliceous cells as a This species produces a maximum of Pyrrhanthera. characteristic part of the leaf anato- eight cleistogenes at each node of Danfhonia my in all areas. the flowering culm, and, late in the Danthonia shows marked disjunc- Cleisfogenes in Danthonia growing season, the terminal cleis- tion in range of its species. Tem- This report contains information togenes protrude from the sheath. perature regions have species con- on Danthonia in the Jackson Hole D. unispicata produces 2 to 3 cleis- centrations in , south area of Wyoming. It is designed to togenes at a node, but seldom do Australia and New Zealand, South show (1) which species display a they extend beyond the upper por- America, and finally North America. cleistogamous condition, (2) cleis- tion of the sheath until the flowering The Eurasian continent is the poor- togene location, attachment, and culm has dehisced from the plant. est in representation with one spe- number on the cleistogamous species, A smaller number of cleistogenes cies in the Mediterranean region (D. (3) nodal disarticulation occurrence, is produced per node in the terminal provincialis) and two in the Him- and (4) germination of cleistogamic portion of the flowering culms in alaya Mountains (D. cachemyrianu and chasmogamic seeds. the species D. unispicata and D. cali- and D. jacquemontii). Except for oc- Four species of Danthonia occurr- fornica. Although there may be the currence of ing naturally in the flora of Jackson same number of lemmas and paleas var. americana on the western Hole, Teton County, Wyoming, fur- at each node, the cleistogenes are coastal regions of North America and nished the basic materials. These definitely smaller and more likely South America, the species are species are D. spicata, D. unispicata, to be rudimentary. endemic to their areas. However, in D. intermedia, and D. californica. In Weatherwax (1928) compared North America four centers of dis- addition, D. parryi was collected cleistogenes and chasmogamous tribution occur: Mexico (D. filifolia), from Pole Mountain in the Medicine seeds produced in the inflorescense the Caribbean Sea (D. domingensis Bow National Forest near Laramie, as follows: 294 DOBRENZ AND BEETLE

three cleistogamous species of Dan- thonia at different times during the stages of growth. This breaking oc- curred just below each node, the basal ones being the first to fall. Actual separation of the terminal internodes occurred after the flower- ing culm had fallen from the plant. Each segment of the flowering culm was composed of the internode, basal node, the sheath, and the cleis- togenes. At this stage of maturity the sheath was starting to loosen; thus all the cleistogenes may not have been present. D. unispicata was the first of the cleistogamous species to begin nodal disarticulation. In late July and early August the flowering culms

FIG. 1. Node and internode from Danthonia californica showing cleistogcne location, attachment, and number.

“In some cases, the two types of cence. Basal cleistogenes are longer disarticulated florets differ greatly and, in general, larger than the in appearance because of the vari- chasmogamic seeds. In D. spicata, able nature of the lemma; but there cleistogenes and chasmogamic se&ds seems to be no consistent difference have close resemblance, and it was in the caryopsis. Seeds from both difficult to determine which were sources germinate alike; and seed- produced at the joints and which FIG. 2. A comparison in the size of seeds ling plants observed until flowering, from the normal . produced in the normal inflorescence the second season after germination, Nodal DisarticuZation.-Disarticu- (lower caryopsis) of Danthonia unispi- are alike in appearance and vigor.” lation or breaking of the flowering cata, and cleistogenes produced at the Table 1 illustrates the number of culm at each joint occurs in the nodes (upper caryopsis) . cleistogenes produced in the cleis- togamous species with the number Table 1. Comparison of chasmogamic seed production with cleisfogene pro- of seeds produced in these same duction among four Danthonia species.1 plants. D. unispicata and D. cali- - -~____~ fornica produce more cleistogenes D. D. D. D. - than chasmogamous seeds. Cleisto- Species unispicata spicata intermedia californica ___ ~_ gene production in D. spicata is rela- No. spikelets per tively low compared with the chas- flowering culm 1 5-6 7-8 3-4 mogamous seeds. No. florets per spikelet 4-5 5-6 3-4 5-6 Cleistogenes on D. unispicata are No. nodes with larger and sometimes twice the size cleistogenes 3-4 2 none 5-6 of chasmogamic seeds (Fig. 2). No. cleistogenes Size differences also are char- per node 2-3 1 none 6-7 Total no. seeds acteristic of D. californica. Since this species produces as many as eight per flowering culm 4-5 27-28 25-26 21-33 cleistogenes per joint, many of the Total no. cleistogenes per flowering culm 8-9 2 none 25-36 terminal ones are somewhat shorter -_ than the seeds from the inflores- 1 Means based on 100 flowering culms of each species. CLEISTOGENES 295

were scattered at the base of the plant. Lack of culms gave the plant a naked look because only basal leaves remained. At this time of year, the appearance of the plant is very much the same as it was in the spring before any flowering culms were produced. Just before nodal disarticulation occurred, the flower- ing culms turned a reddish color, which made D. unispicata easy to locate. Evidently, when the red color first appeared, the nutrient supply to the flowering culms had been dis- continued because of the separation of the first joint from the base of the plant, and curing the grass had started. Internodes containing only a por- tion of the stem and the sheath were found scattered and intermingled among the plants in the locality of FIG. 3. Small seedlings of Danthonia rmispicata showing their abundance and D. unispicata, particularly when clustered distribution around the parent plant. game or livestock h,ad been present. D. culifornicu disarticulated in the Table 2. Comparison of perceniage germination of chasmogamic seeds and same manner as D. unispicutu except cleisfogenes under various treatments. that the entire plant was more ma- ture before this process began. Joints Percentage did not break into separate entities Species Type of seed Treatment germination as easily in D. culifornica, and the D. unispicutu Cleistogamic Water and chilled 41 entire culm remained united with Chasmogamic Water and chilled 40 the inflorescence until long after the Cleistogamic Water and non-chilled 66 flowering culm had disarticulated Cleistogamic KN03 and non-chilled 66 at the basal node. This breaking up first occurred approximately in the D. culifornicu Cleistogamic Water and chilled 0 middle of August. Chasmogamic Water and non-chilled 0 Nodal disarticulation of D. spicutu Cleistogamic Water and non-chilled 0 occurred so late in the growing sea- Cleistogamic KN03 and non-chilled 10 son (September 1 to 15) that we Chasmogamic KN0.7 and non-chilled 10 doubt whether such disarticulation D. spicutu Cleistogamic Water and chilled 70 might have any effect on the dis- Chasmogamic Water and chilled 33 tribution and scattering of chasmo- D. intermedia Chasmogamic Water and chilled 95 gamic or cleistogamic seeds. The fact ____ that D. spicutu produced only a few cleistogenes in addition to the late, showed many small seedlings new plants. There was a wide and only partial, nodal disarticula- clustered around the baseof each range in germination percentage tion of the flowering culms may in- parent plant of D. unispicata of the cleistogamous species dicate that it is more closely related (Fig. 3). How many of these to the two North American species, (Table 2) . D. culifornicu cleis- D. intermedia and D. purryi. Both of small plants were produced by togenes germinated only when these species also occurred in Wyo- cleistogenes and how many from the blotters had been soaked ming, but only D. intermedia was chasmogamic seeds was impossi- with potassium nitrate. Cleis- present in Jackson Hole. Neither ble to determine in the field. togenes of D. spicutu had the displayed nodal disarticulation. However, seedling abundance highest percentage (70%)) with Germination.-The purpose of suggests that cleistogenes are an those of D. unispicutu second the germination tests was to de- important means of reproduction (66%) * termine whether cleistogenes are for at least this cleistogamous D. intermedia displayed the viable, and how their percentage species of Danthoniu in Jackson highest germination percentage germination compared with that Hole. of chasmogamic seeds while D. of chasmogamic seeds which Cleistogenes from the three culifornicu had the lowest per- were taken from the same plant. species, D. spicuta, D. unispicutu, centage germination when both Observations during the early and D. culifornicu proved to be chasmogamic seeds and cleis- part of the growing season viable and capable of producing togenes were compared. This 296 DOBRENZ AND BEETLE

may partially explain the limited the base of the flowering culm BROWN, W. V. 1952. The relation of distribution of this species in had a cleistogene present. D. soil moisture to cleistogamy in Stipa Bot. Gaz. 113: - the Jackson Hole area. Cleis- produced no cleis- leucotricha. intermedia 438-444. togenes in the other two cleis- togenes in Jackson Hole. CAMPBELL,J. B., K. F. BEST, ANDA. C. togamous species of Dunthania Cleistogenes were more abun- BUDD. 1956. Ninety-nine range for- compared favorably with the dant per flowering culm than age plants of the Canadian prairies. Canada Dep. Agri., Ottawa, On- germination of chasmogamic were the chasmogamic seeds in tario. Publ. No. 964. 99 p. (Espe- seeds. the two species D. unispicutu and cially p. 26). The potassium nitrate treat- D. culifornicu. CHASE, A. 1918. Notes on the cleis- ment was the only condition Nodal disarticulation occurred togamy of grasses. Bot. Gaz. 5: 134- 136. under which both types of seeds in the three cleistogamous spe- from D. caZifornica germinated. DYKSTERHUIS. 1965. Axillary cleis- cies and proved to be a means togenes in Stipa Zeucotricha and Therefore it is possible that cer- by which cleistogenes and chas- their role in nature. Ecology 26: - tain elements in the soil can mogamic seeds were scattered, 195-199. affect germination of this spe- particularly in the localities of HACKEL, E. 1906. “Ueber Kleistog- cies. amie bei den Grasern.” Oest. Bot. D. culifornicu and D. unispicata. Zeit. 56: 81-88, 143-154, 180-186. Plants from the germinated Cleistogenes were found to be HITCHCOCK,A. S. 1935. Manual of the cleistogenes and chasmogamic capable of producing new plants grasses of the United States. U. S. seeds were transplanted into and therefore are described as a Dep. Agric. Misc. Pub. No. 200. 1040 p. pots in the greenhouse. After means of reproduction for the two months there appeared to be HITCHCOCK,A. S. 1951. Manual of the cleistogamous species in Jackson grasses of the United States. 2nd. no difference in appearance and Hole. edition (Rev. by Agnes Chase), vigor of the two kinds of seed- U. S. Dep. Agric. Misc. Publ. 200. lings. LITERATURE CITED 1051 p. LINNAEUS, C. 1753. Species plantar- ALLAWAY, W. H. 1957. Soil, the year- Summary and Conclusions urn. W. Junk, Berlin W., Kurfiir- book of agriculture. U. S. Dep. stendam, 201.1200 p. (Especially p. D. californica and D.unispicata Agric., , D. C. 784 p. were found to be polycleisto- (Especially p. 67-72). 55-59). MEYER, B. S., AND D. B. ANDERSON. gamous with more than one ARBER, A. 1934. The Gramineae. 1952. Plant Physiology. D. Van cleistogene produced at each Cambridge University Press, Lon- Nostrand Co., Inc., Princeton, N.J. joint, and all attached by an axis don. 480 p. (Especially p. 164-206). 784 p. (Especially p. 335-366). or rachilla. D. spicata was found BEETLE,A. A. 1961. Cleistogene for- UPHOF,J. C. 1938. Cleistogamic flow- ers. Bot. Rev. 4:21-49. to be monocleistogamous, pro- mation-an example of epharmonic form and distribution pattern in WEATHERWAX, P. 1928. Cleistogamy ducing only one cleistogene per the Gramineae. Wyoming Range in two species of Danthonia. Bot. joint and often only one joint at Manage. Issue No. 154. p. 3. Gaz. 86: 104-109.

perennial grass. A basic con- (1937a, 193713, 1938) stressed the Range Reseeding Success on sideration for reseeding is the importance of soil treatment, The Tonfo National Forest, discovery of long-lived, palatable covering seed and protecting and otherwise adaptable species. seeded areas until establishment This study reports on perennial occurred. Glendening (1937c) B. IRA JUDD grasses that have survived 16 advocated the use of mulch to Professor of Agronomy, Arizona years or more under arid condi- establish stands. Cassady (1937) State University, Tempe. tions on the Tonto National For- listed general suggestions on re- Highlight est of central Arizona. Planting seeding incorporated in the orig- Longevity of range plantings is trials, methods, and longevity of inal plans. Crider’s (1945) evalu- important io those interested in species are appraised for four ation of the three introduced range resforaiion by this means. An analysis of plantings of 1945 and different growing conditions. lovegrasses proved of value in 1946 through 1965 provide informa- Revegetation of range lands in deciding where each species was fion on longevity for four different Arizona, as elsewhere, was an used. This report supplements environments on the Tonto National Forest of central Arizona. Profec- early undertaking of research. the preliminary publication by five brush mulch was highly impor- Griffiths (1907) concluded that Judd (1948) on this study. tariff for stand establishment under reseeding on an economic basis Sfudy Areas the conditions of these iesfs. is applicable to those areas where The Tonto National Forest of Many rangelands in Arizona requisite moisture occurs. Samp- 2,960,567 acres is located in cen- can be benefited by reseeding to son (1913) and Glendening tral Arizona. It includes the